SHARMA, NIVEDITAKUMAR, VIJAY2019-08-062019-08-062019-04http://krishikosh.egranth.ac.in/handle/1/5810119536ABSTRACT The present investigation was an attempt made for the isolation and identification of most potent PGPR and to test their efficacy for plant growth promotion of Triticum aestivum. In total 73 bacterial isolates were isolated from six different sites of Solan and Sirmour district. All isolates were screened out for multifarious plant growth promoting traits viz. phosphate solubilization, siderophores, protease, chitinase, cellulase, production of HCN, ammonia and plant growth regulators. Out of total 73 isolates, 60 isolates were positive for P-solubilization, 61 produce siderophore, 62 were positive for protease, 6 were positive for cellulase and 15 were positive for chitinase production, Only 13 showed HCN production and all the isolates showed ammonia production. Three potential PGPR i.e. Dh-7, Kn-7 and De-21 were selected based on criteria of total PGP potential and examination of individual PGP attribute. These isolates were identified as De-21 Pseudomonas putida |MH362752|, Kn-7 Stenotrophomonas maltophilia |MH362753| and Dh-7 Bacillus pumilus |MH362754| by 16S rRNA gene technique. These screened isolates were further examined for the production of plant growth regulators viz., auxins was recorded in the range of 24-64 µg/ml, gibberellins production was found in the range of 110-550 µg/ml, whereas cytokinins production was in the range of 120-370 µg/ml. All the three screened isolates were selected for the net house and field trial at Dharja and Damrog. Treatments of individual strains and their consortia have different effects on the various plant growth promoting parameters. The germination percentage of seeds in net house was recorded 100 % in most of treatments except i.e 95.33% in Kn-7+De-21 with 50% NPK and 96.33% in Dh-7+De-21 with 50% NPK. The maximum shoot height i.e 19.83 cm, chlorophyll ‘a’ content 0.138 mg/g, chlorophyll ‘b’ content 0.264 mg/g and total chlorophyll content 0.386 mg/g were observed under net house conditions.The seeds germination percentage was recorded 100% in each treatment along with control plants (without PGPR inoculations) at both the site except control plants with 50% NPK (95%) at Dharja. The maximum shoot growth i.e 34.13 cm was noticed at Dharja and 24.04 cm was recorded at Damrog. The maximum number of leaves 19 were recorded at Dharja and 18 were recorded at Damrog site. The highest tiller number was recorded 7 per plant at Dharja while it was highest i.e 5 per plant at Damrog site. The maximum size of spike i.e 4.90 cm and 4.40 cm was found at Dharja and Damrog respectively. Maximum grain yield was found in consortia of three isolates with 100% NPK (208.76 gm) with an increase of 47.18% increased closely followed by consortia of three isolates (208.56 gm) with 47.13% increase over control plants. On the basis of these findings, consortia of three isolates (Pseudomonas putida De21, Stenotrophomonas maltophilia Kn-7, Bacillus pumilus Dh-7) with 100% NPK was found to be the best treatment among closely followed by consortia of three isolates without any chemical fertilizer. Thus consortia of potential PGPR strains could be used as biofertilizer for sustainable cultivation of Triticum aestivum of which could be helpful in its cultivation. The growth promotion in the various plant parameters of wheat with consortia treatment over control (without PGPR inoculation) have successfully fulfilled the main objectives of this study.ennullThesis